DE102007044617A1 - Compounder injection molding machine has melt line and injection duct that are interconnected over switching valve with three shift positions, where injection duct is released for injection operation - Google Patents

Abstract

The compounder injection molding machine has a plastification device. A melt line (70) and an injection duct (82) are interconnected over a switching valve (90) with three shift positions. The melt line is locked in a secondary switching position or injecting position, and the injection duct is released for an injection operation. A melt, arriving from the melt line, is decanted into a collecting space (56) of a piston spraying apparatus in a third switching position or decanting position.

Description

The The invention relates to a compounder injection molding machine, according to the preamble of claim 1 or claim 5th

A compounder injection molding machine, sometimes called also Spritzgießcompounder, taken by itself from the prior art, for example from the DE10230331 B3 and the EP1306187B1 , With reference to the 1 If such a known compounder injection molding machine to be described in more detail below.

The known compounder injection molding machine comprises as plasticizing 11 a twin-screw extruder with a screw cylinder 10 , in which two paraxial screws 16 . 18 axially non-displaceably mounted rotatably. About a screw conveyor 13 and a funnel 14 becomes plastic material from a dosing station 12 introduced into the interior of the screw cylinder and by rotation of the screw 10 plasticized by means of a drive and conveyed in the direction of a discharge end, on which the worm cylinder 10 in a connecting line 32 empties. Between the funnel 14 and the discharge end of the cylinder may, if necessary, a Treibmittelzufuhrstation 20 be provided, the propellant in the form of gas by means of a pump 8th from a gas storage in the preferably already plasticized plastic material initiates. The connection line 32 flows into a cache 40 ie a collection room 47 a storage cylinder 45 in which a storage piston 42 slidably received. The collection room 47 is over a line 70 with a collection room 56 a piston injection device 50 connected. The outlet end of the plenum 56 is about one with a shut-off 22 equipped injection channel 82 with a mold fastened in a closing unit 60 connected.

During operation, plastic material is continuously fed from the extruder and fills the plenum 56 the arrangement 50 , where the piston 52 displaced or regulated withdrawn from the nachfließenden plastic mass, and wherein the obturator 22 closed is. When the plenum 56 is filled to a predetermined level with plastic material, the connection between the buffer 40 and the injection cylinder assembly 50 over a barrier organ 72 interrupted, the obturator 22 opened, and the plasticized plastic mass is from the piston 52 that by a drive 58 is operated in the form 60 injected.

At the same time it collects in the collection room of the cache 40 the plastic material supplied continuously from the extruder. In order to allow the most constant possible pressure conditions, the piston 42 of the cache 40 connected to a displacement device. The displacement device comprises two piston-cylinder arrangements 44 and 46 wherein the respective pistons via a connecting member 48 with the piston 42 of the cache 40 are connected. By applying the piston of the piston-cylinder units 44 . 46 with a pressure medium, the pistons can be moved and move accordingly over the link 48 the piston 42 of the cache 40 ,

In the course of the line 32 is also a blocking and relief body 30 , Also called start-up valve, arranged with which the connection between the discharge port of the extruder and the buffer 40 can be interrupted. If, for example, due to a fault in the extruder plastic material is supplied with too low pressure or in case of malfunction in the injection unit plastic material can not be processed further and the capacity of the buffer is exhausted, locks the organ 30 the compound so that the plastic material downstream of the organ 30 by means of the cache 40 is maintained at the required pressure. It can be the organ 30 with a derivative 34 Be provided over the nachgefördertes plastic material is discharged from the system, for example in a water bath 74 , The barrier and relief organ 30 includes a body 31 , in the one hand, the ejecting end of the worm cylinder 10 on the other hand, the connection line 32 , In the body 31 is a pestle 33 slidably mounted, with a piston-cylinder unit 35 connected is. From a hydraulic fluid pump 39 is hydraulic fluid via lines 36 or 37 the piston-cylinder unit is fed so that the plunger 33 according to a position of the control valve 38 can be moved. In this case, the arrangement is preferably made such that the plunger can be adjusted to a first position in which the discharge end of the worm cylinder 10 with the derivative 34 connected, and at least one second position in which the organ 30 the discharge end of the worm cylinder 10 with the connection line 32 combines. In addition, another position (closure position) may be provided, in which the plunger 33 the discharge end of the worm cylinder 10 closes.

From the WO 86/06321 A1 is another compounder injection molding machine is known which has no buffer and in which the twin-screw extruder is stopped during the injection process (see 2 in WO 86/06321 A1 ).

A compounder injection molding machine of the type mentioned is comparatively complex which, on the one hand, is associated with corresponding costs and, on the other hand, makes operation and maintenance costly. For example, in shut-off in melt channels, whether as a sliding or rotary unit, (for example, the locking member 72 in 1 ) In principle, the risk that air is drawn in via the sealing surfaces of the obturator or that burned plastic material enters the melt channel. The latter can be avoided if a certain leakage over the gap between the valve housing and the valve body is provided, so that plastic material is always conveyed through the higher pressure in the melt channel only from the melt channel away. However, the material leakage depends on the viscosity of the plastic mass on the one hand and the gap size of the leakage on the other hand, which may lead to significant material leaks on the sealing surfaces under certain circumstances. This material must be removed regularly for safety reasons, which leads to increased maintenance. The directly downstream of the extruder start-up and discharge valve (locking and discharge organ 30 in the 1 ) also represents an extension of the melt line to the width of the Anfahrventils. This can lead to procedural restrictions in durable zeitzeitischem plastic material or highly viscous plastic material due to the pressure losses occurring.

outgoing This is the object of the invention, a compounder injection molding machine specify, on the one hand has a simplified construction and with the other hand, the aforementioned disadvantages of known compounder injection molding machine can be avoided.

The This problem is solved by a compounder injection molding machine with the features of the independent claims 1 and 5. Advantageous embodiments and further developments can be found in the subclaims.

In the first solution according to claim 1 are the Coming from the extruder melt line and the piston of the syringe for injection mold leading injection channel over a switchable valve with at least three switching positions with each other connected, wherein in a first switching position (position "start") the incoming melt from the melt into the environment can be discharged, wherein in a second switching position (Position "injection") shut off the melt line and at the same time the injection channel for the injection process is released, and wherein in a third switching position (position "decanting") the from the melt line incoming melt into the plenum of the Reciprocating syringe device can be transferred. The valve becomes directly in the crossing area of melt line and injection channel installed, d. H. the melt channel opens in the switching position "transfer" over the valve into the injection channel.

In a second solution according to claim 5, a switchable valve with at least three switching positions is provided in the melt channel, wherein in a first switching position (position "start"), the incoming of the melt line melt can be discharged into the environment, wherein in a second Switching position (injection position) the melt line is shut off and in a third switch position ("transfer" position), the melt line is released.The valve can be arranged in the vicinity of the intersection of the melt line and the injection channel, but it can also be at another Position can be provided in the melt channel, for example, at the location of the obturator 72 in the 1 ; In this case, the melt channel can also open directly into the plenum of the piston injection device, as shown in the 1 is shown.

in the Difference to the above-mentioned prior art are at Both solutions the functionalities of a starting valve as a blocking and relieving organ at the extruder outlet on the one hand and those of a shut-off (or transfer valve) in the melt line to the piston injection unit on the other hand in a integrated single valve. By eliminating the leakage on one additional obturator will reduce the maintenance of the Operator of the compounder injection molding machine reduced. Furthermore, the flow path length of the plastic material is reduced from the extruder outlet to the piston injection device. Furthermore, since both the starting valve and the shut-off or overflow valve over need to have control and regulation, is by merging the functions of machine investment reduced, since only a single control and regulation required is.

Hereinafter, the invention with reference to embodiments and with reference to the 2 to 6 be described in more detail. Show it:

2 Compounder injection molding machine according to the invention;

3a Connection area of melt line and injection channel according to a first embodiment;

3b Top view of the valve body of the first embodiment from above;

3c View of the valve body of the first embodiment from the front;

4a Connection area of melt line and injection channel according to a second embodiment;

4b Top view of the valve body according to the second embodiment from above;

4c View of the valve body according to the second embodiment from the front;

5a Connection area of melt line and injection channel according to a third embodiment;

5b Top view of the valve body according to the third embodiment from above;

5c View of the valve body according to the third embodiment from the front;

6 Connection area of melt line and injection channel according to a fourth embodiment.

The embodiment of a compounder injection molding machine according to the invention according to the 2 is different from the one in the 1 in that the blocking and relieving organ 30 with the associated peripheral parts and the obturator 72 are omitted and instead a melt line 70 from the end of the twin screw extruder 10 about the cache 40 into the connection area 80 leads where the melt line 70 in the injection channel 82 empties. Optionally, the cache 40 can also be omitted, for example, if for a short period melt can be buffered in the twin-screw extruder itself or if the twin-screw extruder is stopped. If no foamed plastic moldings are to be produced, the blowing agent supply station can also be used 20 omitted.

The design of the connection area 80 is for a first embodiment of the invention in the 3a to 3c shown in more detail. Between the front end of the piston injection unit 50 and the injection channel 82 is a valve 90 , consisting of a valve housing 92 and a bolt-shaped valve body 94 arranged. The valve housing 92 has two orthogonal channels 91 and 93 on, with the melt line 70 in the channel 91 opens and the channel 93 the outlet end of the plenum 56 and the injection channel 82 combines. In the crossing area of the canals 91 and 93 has the valve body 92 a cylindrical bore, wherein the cylinder longitudinal axis orthogonal to that of the melt line 70 and injection channel 82 spanned level lies. Along this cylinder longitudinal axis of the bolt-shaped valve body 94 be moved, so with the valve 90 or the valve body 94 different switch positions can be taken. The valve body 94 is in the 3b in plan view from above and in the 3c in the view from the front (view from the direction of the obturator 22 shown); he will be in the 3a in the direction of the arrow in the valve body 92 used, ie from above into the plane of the drawing sheet into it. The valve body 94 has three adjacent channels 1 . 2 and 3 each of a different course, with which the required for operation and described in more detail below switching positions can be realized. The channel 1 has a curved course; it has an inlet opening E on the upper side of the valve body and an outlet opening A on its rear end side. The channel 2 has a straight line across the valve body, wherein an inlet opening E are provided on the right and an outlet opening A on the left side of the valve body. The channel 3 has an arcuate course, wherein an inlet opening E on the upper side of the valve body and an outlet opening A on the left, ie the collecting space 56 facing side, the valve body is located.

In the switching position (1) is the channel 1 in the crossing area of the melt line 70 and injection channel 82 , That of the melt line 70 incoming plastic material or the melt is discharged to the rear into the environment. This position of the valve body 94 corresponds to the first switching position, ie the position "approach", in the switching position (2) is the channel 2 in the crossing area of the melt line 70 and injection channel 82 , In this position is the passage from the plenum 56 in the injection channel 82 free while the lower end of the melt channel 70 is locked. This position of the valve body 94 corresponds to the second switching position, ie the position "injection" This position is also in the 3a shown. In the switching position (3) is the channel 3 in the crossing area of the melt line 70 and injection channel 82 , In this position is a connection between the melt line 70 and the collection room 56 made, so the collection space 56 with melt from the extruder 10 and / or the cache 40 can be filled. This position of the valve body 94 corresponds to the third switching position, ie the position "transfer".

The design of the connection area 80 is for a second embodiment of the invention in the 4a to 4c shown in more detail. Unlike the 3a to 3c the removal of plastic material takes place downwards, including the valve housing 92 an outlet channel 97 and in the valve body 94 a channel 1' with a straight from top to bottom extending straight Lined course is provided. In the first switching position, ie in the position "start" is the inlet channel 91 with the outlet channel 97 over the canal 1' fluidically connected. Otherwise, this embodiment corresponds to that of the 3a to 3c ,

A third embodiment of the invention is in the 5a to 5c shown. Unlike the 3a to 3c is the valve body 95 designed differently than the valve body 94 and is also not in the crossing area of the channels 91 and 93 but above the channel 93 and thus above the injection channel 82 , In the valve housing is an upper inlet opening 96 and a lower, the channel 91 forming outlet opening provided. So there is a constant connection between the front end of the plenum 56 and the obturator 22 , The valve body 95 is in the 4b in plan view from above and in the 4c in the view from the front (view from the direction of the obturator 22 shown); he will be in the 4a in the direction of the arrow in the valve body 92 used, ie from above into the plane of the drawing sheet into it. The valve body 95 has two channels 4 and 5 of different course on. The channel 4 has a curved course; he has an inlet opening E on the upper side valve body 95 and an outlet opening A at the rear end side thereof. The channel 4 corresponds with respect to its position or its switching position and its course the channel 1 of the valve body 94 , In contrast to the valve body 94 has the valve body 95 at the position (2) via no channel. The channel 5 at the position (3) or for the third switching position a straight line across the valve body, wherein an inlet opening E on the top and an outlet opening A on the underside of the valve body 95 are provided.

In the switching position (1) is the channel 4 in the channel 91 and that of the melt line 70 incoming plastic material or the melt is discharged to the rear into the environment. This position of the valve body 95 corresponds to the first switching position, ie the position "approach" In the switching position (2) is the channel 91 blocked. In this position is the passage from the plenum 56 in the injection channel 82 free while the melt channel 70 is locked. This position of the valve body 95 corresponds to the second switching position, ie the position "injection" This position is also in the 4a shown. In the switching position (3) is the channel 5 in the channel 91 , In this position is a connection between the melt line 70 and the collection room 56 made, so the collection space 56 with melt from the extruder 10 and / or the cache 40 can be filled. This position of the valve body 95 corresponds to the third switching position, ie the position "transfer".

According to a fourth embodiment ( 6 ), the valve may also be at a different location in the course of the melt line 70 are arranged, in which case the injection channel 82 through to the collection room 56 extends and the melt line 70 opens directly into the injection channel; the valve body 95 stays unchanged. For example, at the location of the obturator 72 from 1 a valve housing 92 with an inlet opening or an inlet channel 96 and an outlet port and an outlet port, respectively 91 as well as with a valve body 95 be provided as described above. In the switching position (1) can be discharged as described above melt. In the switching position (2), the passage between the inlet and outlet ports is blocked. In the switching position (3) is connected to the channel 5 a connection between the inlet opening 96 and outlet opening 91 produced. In this embodiment, the melt channel 70 also directly into the collection room 56 instead of the injection channel 82 lead.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 10230331 B3 [0002]
• - EP 1306187 B1 [0002]
• WO 86/06321 A1 [0007, 0007]

Claims (10)

Compounder injection molding machine with a plasticizer ( 11 ), a piston injection device ( 50 ) and with a closing unit with a molding tool ( 60 ), between the plasticizing device and the piston injection device ( 50 ) a melt line ( 70 ) provided with a melt collecting space ( 56 ) of the piston injection device ( 50 ) is connectable, and wherein between the piston injection device ( 50 ) and a mold ( 60 ) an injection channel ( 82 ), characterized in that the melt line ( 70 ) and the injection channel ( 82 ) via a switchable valve ( 90 ) are connected to at least three switching positions, wherein in a first switching position (position "start-up") of the melt line ( 70 ) incoming melt can be discharged into the environment, wherein in a second switching position (position "injection") the melt line ( 70 ) and at the same time the injection channel ( 82 ) is released for the injection process and wherein in a third switching position (position "transfer") from the melt line ( 70 ) incoming melt into the collecting space ( 56 ) of the piston injection device ( 50 ) can be transferred. Compounder injection molding machine according to claim 1, characterized in that the valve ( 90 ) a valve housing ( 92 ) with a cylindrical bore and a therein accommodated, along the cylinder longitudinal axis displaceable bolt-shaped valve body ( 94 ), wherein the cylinder longitudinal axis orthogonal to that of the melt line ( 70 ) and the injection channel ( 82 ) spanned in the plane, wherein in the valve body ( 94 ) three along the cylinder longitudinal axis adjacent channels ( 1 . 1' . 2 . 3 ) are each provided of different course, each channel belongs to a switching position and wherein by moving the valve body ( 94 ) along the cylinder axis the switching positions can be approached. Compounder injection molding machine according to claim 2, characterized in that the outlet opening (A) of the channel (A) 1 ) for the first switching position (position "start") on one of the end faces of the bolt-like valve body ( 94 . 95 ) lies. Compounder injection molding machine according to claim 2, characterized in that the valve body ( 92 ) an inlet opening or an inlet channel ( 91 ) and an outlet opening or an outlet channel ( 97 ), and that the channel ( 1' ) has a straight course transverse to the cylinder longitudinal axis, so that in the first switching position (position "approach") the inlet opening or the inlet channel ( 91 ) and the outlet opening or the outlet channel ( 97 ) are fluidically connected with each other. Compounder injection molding machine with a plasticizer ( 11 ), a piston injection device ( 50 ) and with a closing unit with a molding tool ( 60 ), between the plasticizing device and the piston injection device ( 50 ) a melt line ( 70 ) provided with a melt collecting space ( 56 ) of the piston injection device ( 50 ) is connectable, and wherein between the piston injection device ( 50 ) and the mold ( 60 ) an injection channel ( 82 ), characterized in that in the melt channel ( 70 ) a switchable valve ( 90 ' ) is provided with at least three switching positions, wherein in a first switching position (position "start-up") of the melt line ( 70 ) incoming melt can be discharged into the environment, wherein in a second switching position (position "injection") the melt line ( 70 ) is shut off and wherein in a third switching position (position "transfer"), the melt line ( 70 ) is released. Compounder injection molding machine according to claim 5, characterized in that the valve ( 90 ' ) a valve housing ( 92 ) with a cylindrical bore and a therein accommodated, along the cylinder longitudinal axis displaceable bolt-shaped valve body ( 95 ), wherein the cylinder longitudinal axis orthogonal to the melt line ( 70 ), wherein in the valve body ( 95 ) two adjacent channels ( 4 . 5 ) are each provided by different course, of which the one channel ( 4 ) to the first switch position and the other channel ( 5 ) belong to the third switching position, and wherein the shift positions can be approached by moving the valve body along the cylinder longitudinal axis. Compounder injection molding machine according to claim 6, characterized in that the outlet opening (A) of the channel (A) 1 . 3 ) for the first switching position (position "start") on one of the end faces of the bolt-like valve body ( 94 . 95 ) lies. Compounder injection molding machine according to claim 6 or 7, characterized in that the bolt-shaped valve body ( 95 ) above one in the valve housing ( 92 ) and the collecting space ( 56 ) with the injection channel ( 82 ) connecting channel ( 93 ) is located. Compounder injection molding machine according to claim 6 or 7, characterized in that in the course of the melt line ( 70 ) a valve housing ( 92 ), which has an inlet opening ( 96 ) and an outlet opening ( 97 ), each with a portion of the melt line ( 70 ) are connected. Compounder injection molding machine according to one of the preceding claims, characterized ge indicates that between the plasticizing device ( 11 ) and the piston injection device ( 50 ) a cache ( 40 ) is intended for melt.